Article

Receptor activator of NF-kappaB Ligand (RANKL) expression is associated with epithelial to mesenchymal transition in human prostate cancer cells.

Molecular Urology and Therapeutics Program, Department of Urology and Winship Cancer Institute, Emory University School of Medicine, 1365B Clifton Road, NE, Atlanta, GA 30322, USA.
Cell Research (Impact Factor: 11.98). 08/2008; 18(8):858-70. DOI: 10.1038/cr.2008.84
Source: PubMed

ABSTRACT Epithelial-mesenchymal transition (EMT) in cancer describes the phenotypic and behavioral changes of cancer cells from indolent to virulent forms with increased migratory, invasive and metastatic potential. EMT can be induced by soluble proteins like transforming growth factor beta1 (TGFbeta1) and transcription factors including Snail and Slug. We utilized the ARCaP(E)/ARCaP(M) prostate cancer progression model and LNCaP clones stably overexpressing Snail to identify novel markers associated with EMT. Compared to ARCaP(E) cells, the highly tumorigenic mesenchymal ARCaP(M) and ARCaP(M1) variant cells displayed a higher incidence of bone metastasis after intracardiac administration in SCID mice. ARCaP(M) and ARCaP(M1) expressed mesenchymal stromal markers of vimentin and N-cadherin in addition to elevated levels of Receptor Activator of NF-kappaB Ligand (RANKL). We observed that both epidermal growth factor (EGF) plus TGFbeta1 treatment and Snail overexpression induced EMT in ARCaP(E) and LNCaP cells, and EMT was associated with increased expression of RANKL protein. Finally, we determined that the RANKL protein was functionally active, promoting osteoclastogenesis in vitro. Our results indicate that RANKL is a novel marker for EMT during prostate cancer progression. RANKL may function as a link between EMT, bone turnover, and prostate cancer skeletal metastasis.

0 Followers
 · 
99 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Purpose: MicroRNAs in the delta-like 1 homolog - deiodinase, iodothyronine 3 (DLK1-DIO3) cluster have been shown to be critical for embryonic development and epithelial to mesenchymal transition (EMT). DLK1-DIO3 cluster miRNAs are elevated in the serum of metastatic cancer patients. However, the biological functions of these miRNAs in the EMT and metastasis of cancer cells are poorly understood. We previously demonstrated the oncogenic and metastatic role of miR-409-3p/5p, a member of this cluster, in prostate cancer (PCa). In this study, we defined the role of miR-154* and miR-379, two key members of this cluster, in PCa progression and bone metastasis in both cell line models and clinical specimens. Experimental design: Genetic manipulation of miR-154* and miR-379 was performed to determine their role in tumor growth, EMT and bone metastasis in mouse models. We determined the expression of miR-154* in prostate cancer clinical samples and bone metastasis samples using in situ hybridization and quantum dot labeling. Results: Elevated expression of miR-154* and miR-379 was observed in bone metastatic PCa cell lines and tissues, and miR-379 expression correlated with PCa patient progression-free survival. Intracardiac inoculation (to mimic systemic dissemination) of miR-154* inhibitor-treated bone metastatic ARCaPM PCa cells in mice led to decreased bone metastasis and increased survival. Conclusion: miR-154* and miR-379 play important roles in PCa biology by facilitating tumor growth, EMT and bone metastasis. This finding has particular translational importance since miRNAs in the DLK1-DIO3 cluster can be attractive biomarkers and possible therapeutic targets to treat bone metastatic PCa.
    Clinical Cancer Research 10/2014; DOI:10.1158/1078-0432.CCR-14-1784 · 8.19 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Increased bone marrow adiposity is a common feature of advanced age, obesity and associated metabolic pathologies. Augmented numbers of marrow adipocytes positively correlate with dysregulated bone remodeling, also a well-established complication of metastatic disease. We have shown previously that marrow adiposity accelerates prostate tumor progression in the skeleton and promotes extensive destruction of the bone; however, the factors behind adipocyte-driven osteolysis in the skeletal tumor microenvironment are not currently known. In this study, utilizing in vivo diet-induced models of bone marrow adiposity, we reveal evidence for positive correlation between increased marrow fat content, bone degradation by ARCaP(M) and PC3 prostate tumors, and augmented levels of host-derived CXCL1 and CXCL2, ligands of CXCR2 receptor. We show by in vitro osteoclastogenesis assays that media conditioned by bone marrow adipocytes is a significant source of CXCL1 and CXCL2 proteins. We also demonstrate that both the adipocyte-conditioned media and the recombinant CXCL1 and CXCL2 ligands efficiently accelerate osteoclast maturation, a process that can be blocked by neutralizing antibodies to each of the chemokines. We further confirm the contribution of CXCR2 signaling axis to adiposity-driven osteoclastogenesis by blocking fat cell-induced osteoclast differentiation with CXCR2 antagonist or neutralizing antibodies. Together, our results link CXCL1 and CXCL2 chemokines with bone marrow adiposity and implicate CXCR2 signaling in promoting effects of marrow fat on progression of skeletal tumors in bone.
    Clinical and Experimental Metastasis 03/2015; DOI:10.1007/s10585-015-9714-5 · 3.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Increased bone marrow adiposity is a common feature of advanced age, obesity and associated metabolic pathologies. Augmented numbers of marrow adipocytes positively correlate with dysregulated bone remodeling, also a well-established complication of metastatic disease. We have shown previously that marrow adiposity accelerates prostate tumor progression in the skeleton and promotes extensive destruction of the bone; however, the factors behind adipocyte-driven osteolysis in the skeletal tumor microenvironment are not currently known. In this study, utilizing in vivo diet-induced models of bone marrow adiposity, we reveal evidence for positive correlation between increased marrow fat content, bone degradation by ARCaP(M) and PC3 prostate tumors, and augmented levels of host-derived CXCL1 and CXCL2, ligands of CXCR2 receptor. We show by in vitro osteoclastogenesis assays that media conditioned by bone marrow adipocytes is a significant source of CXCL1 and CXCL2 proteins. We also demonstrate that both the adipocyte-conditioned media and the recombinant CXCL1 and CXCL2 ligands efficiently accelerate osteoclast maturation, a process that can be blocked by neutralizing antibodies to each of the chemokines. We further confirm the contribution of CXCR2 signaling axis to adiposity-driven osteoclastogenesis by blocking fat cell-induced osteoclast differentiation with CXCR2 antagonist or neutralizing antibodies. Together, our results link CXCL1 and CXCL2 chemokines with bone marrow adiposity and implicate CXCR2 signaling in promoting effects of marrow fat on progression of skeletal tumors in bone.
    Clinical and Experimental Metastasis 03/2015; epub ahead of print. · 3.73 Impact Factor

Full-text (2 Sources)

Download
16 Downloads
Available from
May 30, 2014